Oftentimes, when a donated organ is kept on ice and submerged in a special solution, it lasts long enough to transfer it to a recipient. The viability depends on the organ; hearts and lungs can only survive outside the body for roughly five hours, while kidneys can last about 24 hours. With a new "supercooling" technique, scientists have managed to keep rat livers viable for four days outside of the body - and, they say, that is only the beginning.

A new technique developed by a team of tissue engineers at the Centre for Engineering in Medicine at Massachusetts General Hospital has opened up new doors into the world of organ donation, Wired reported. A typical human liver lasts about 12 hours after extraction, 24 hours if kept on ice and a special solution, before it is no longer viable and available for organ donation. The new technique called "supercooling" has allowed researchers to keep a rat liver viable for almost four solid days - three and a half days longer than what is considered typical.

The supercooled livers were stored for 72 hours and 96 hours at 21 degrees Fahrenheit, reported Monthly Prescribing Reference. The rats with the 72-hour livers survived an average of three months and those with the 96-hour livers had a 58 percent survival rate, while no rats in the control group who received livers through traditional methods survived.